Thailand has been gripped by political unrest since Thaksin Shinawatra, the then prime minister, was forced out of power in a military coup in 2006.
Last year his supporters, called as red shirt movement, launched agitation against the government.
At least 90 people died and many more went missing in the government crackdown that followed.
The government promised to investigate the entire issue but little progress has been made, while many of the kin of the missing still await any information one year after the protests.
Al Jazeera's Wayne Hay reports from Bangkok.